MANY-BODY POTENTIAL MODEL FOR ZN

A many-body potential model based on the second moment of the tight-bi nding approximation is proposed for computer simulation of lattice def ects in Zn. The constructed potential satisfactorily reproduces the ex perimental data: cohesive energy, equilibrium lattice constants, vacan cy formation energy and elastic constants. except C-33. Mechanical and structural stability has been ensured and the stacking-fault energy h as been determined to be close to the lower end of experimental estima tes. As an application of the model, the monovacancy migration energie s and the formation energy of single self-interstitials are calculated . A significant anisotropy of vacancy migration and a low value of int erstitial formation energy is found, in full accordance with the resul ts of previous experimental and theoretical studies. The shortcomings of spherically symmetric potentials applied to the hcp metals with cia ratios strongly deviating from the ideal value are discussed.